This invention pertains to dental instruments, more specifically, to a means for protecting the operator""s eyes from high intensity lights which are commonly used in dentistry.
Dentists are restoring many tooth cavities with restorative compositions which polymerize and harden when exposed to selected bright lights. Appropriate bright light is available from the distal end of a portable light wand. However, reflections of such bright light from a mouth often reach the dentist""s eyes where they are intense enough to be irritating. The portion of the light which is most effective as a stimulus for the viscous restorative is the blue wave lengths which are traumatic for the operator""s eyes. Never-the-less, it is imperative that the operator view the treatment area clearly with adequate light. Also, if a polymerizing light is held too far from the restorative the intensity and effectiveness of its beam will decrease. Further, the light wand should not be close enough to contact the restorative since contact from a wand assembly will damage the surface form of the restoration. Thus, protective shields have been proposed to protect the operator""s eyes from such harmful reflected radiation.
Available shields exhibit detrimental features. Many shields are designed as cones or parabolic forms which are cumbersome because they require more space and weight. Thus they tend to contact the restorative composition which is likely to cause damage. Prior shields also reflect randomly and generate secondary reflections from glossy mouth tissues. This shield provides a see-through segment with reduced intensities and filtration of blue light for safe viewing of the treatment field but others do not enable adequate monitoring of the treatment field.
U.S. Pat. No. 4,445,858 to Johnson (1984) describes a frustro-conical shield affixed to a fiber optic light wand with a reflective underside. Its conical reflective surface will direct light in arbitrary, unfocused patterns and it is made of opaque polymers which do not provide an adequate view treatment field.
U.S. Pat. No. 4,615,679 to Wyatt (1986) details a frustro-parabolic attachment for a light wand which does not reflect or focus extraneous light. It is formed of a copolymer of ethylene and vinyl acetate which will not provide an adequate view of the treatment field.
U.S. Pat. No. 4,640,685 to Croll (1987) discloses a paddle to be held between a field of treatment and an operator""s eyes. No provision is made to reflect or concentrate stray light. Usually, an operator holds and directs a light wand in one hand and uses the other to deflect lips, tongue and cheeks to permit accessibility. However, it is cumbersome and difficult to control the wand and tissues and also hold the paddle.
U.S. Pat. No. 4,662,842 to Croll (1987) shows a device which purports to obviate the need for a third hand by attaching a paddle to a finger ring. It is made of orange plastic as a light filter, but is awkward and does not adequately collect or redirect reflected light.
U.S. Pat. No. 4,673,353 to Nevin (1987) offers a syringe with an opaque outer veneer to protect the operator""s eyes and a light bearing plunger to activate the hardening of the composition injected by the syringe. The orifice of the cavity tends to be obscured by the opaque cylinder and to make a disruptive contact with a formed restorative composition.
U.S. Pat. No. 4,900,253 to Landis (1990) discloses pigments affixed to a dental mirror which are intended to modify damaging light rays. Because of its limited dimensions, such a mirror will modify some, but neither all nor most of the light reflected.
U.S. Pat. No. 5,288,231 to Kuehn (1994) shows a flat shield of crystalline styrene plastic with crossing slits through which a light wand may be inserted. It offers no light collecting or redirecting advantages.
U.S. Pat. No. 5,509,800 to Cunningham (1996) shows a flat, pigmented and transparent planar device with no collecting or reflecting characteristics.
Additionally, operators have used eyeglass covers and pigmented eyeglass lenses to protect their eyes, but such covers and lenses will not adequately reflect the reflected light.
Accordingly, several objects and advantages of my invention are:
1. to provide a way to protect an operator""s eyes from bright lights used in dental procedures,
2. to provide a means to collect, redirect and utilize reflected light which would otherwise be wasted and
3. to provide a device to focus the primary beam to a limited area.
Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.